the Fruit of Cucurhita. 461 
comparable with the later results, for which this manner of 
calculating the increase proved to be convenient. 
The figure which occurs in the third column opposite the 
first morning reading on Sept. 7, 8, 9 gives the rate of growth 
since the last reading on the preceding evening. 
The results are of small value, but as far as they go they 
agree with later experiments in showing a decrease in rate in 
the afternoon and an increase towards evening. Also in the 
low average growth of the whole night. 
For the following observations on the change in weight of 
the fruit I used a different balance, originally designed by my 
brother Horace as a self-recording instrument. 
It consists of a beam turning on a knife-edge, at one end 
of which the gourd is hung in place of the scale-pan ; at the 
other end of the beam is a scale-pan containing weights not 
quite sufficient to balance the fruit : the equipoise is effected 
by a spiral spring which supports the heavier end of the beam. 
If the fruit gains weight, the fruit-end of the beam will sink, 
and will stretch the spring until a new position of equilibrium 
is attained ; in this way the movement of the beam repre- 
sents changes in weight of the fruit. The movement of 
the beam is magnified by prolonging one of its arms to 
a length of 62 cm. from the knife-edge ; this long arm ends in 
a fine index, and its position is read on a scale divided into 
millimeters. 
The index is brought back to the zero by adding weight to 
the scale-pan. The following figures give the weight so 
G rams. 
Mm. 
Value of 
one gram. 
Sept. 10, 1892. 
40 
hi 
2-8 mm. 
„ n „ 
45 
129.5 
2’9 » 
>) 12 » 
3 2 
89 
2-8 „ 
» 13 » 
20 
62 
3 -i » 
„ 14 m 
40 
ll 9 
3 -o » 
„ 16 „ 
40 
117 
2-9 1 
» 18 „ 
40 
103 
26 „ 
„ 19 » 
30 
65 
2 - 3 ? „ 
>, 20 „ 
50 
147-5 
3 -o „ 
